public class Main {
    public static void main(String[] args) {
        Approver director = new Director();
        Approver vicePresident = new VicePresident();
        Approver president = new President();
        Approver congress = new Congress();

        director.setSuccessor(vicePresident);
        vicePresident.setSuccessor(president);
        president.setSuccessor(congress);

        director.processRequest(new PurchaseRequest(30000));
        director.processRequest(new PurchaseRequest(70000));
        director.processRequest(new PurchaseRequest(200000));
        director.processRequest(new PurchaseRequest(600000));
    }
}